Method of manufacturing microwave reaction device and microwave reaction device

ABSTRACT

The present invention relates to a method of manufacturing a micro reactor device that includes a tubular reactor ( 1 ) as a flow path, for allowing reaction species to react in the reactor ( 1 ). The micro reactor device is manufactured by forming a particle layer ( 2 ) on an inner wall of the reactor ( 1 ). The particle layer ( 2 ) can be formed by causing a dispersion liquid of particles to flow through the reactor ( 1 ) and drying. In this way, it is possible to provide a method of manufacturing a micro reactor device having an inner wall modified so that the reaction species can react more efficiently, and to provide the micro reactor device.

TECHNICAL FIELD

The present invention relates to a method of manufacturing a microreactor device and relates to a micro reactor device. In particular, thepresent invention relates to a method of manufacturing a micro reactordevice that can attain high efficiency and precise catalyst reactions asa catalyst reactor device, can be used as an electrochemical reactordevice, and can be provided with a sensor, and relates to the microreactor device.

BACKGROUND ART

A micro reactor device has, for example, a tubular reactor having asmall diameter. By causing various reaction species to pass through thereactor as a flow path, various reactions, such as production ofmaterials and catalyst reactions, are caused. In the micro reactordevice, walls of the reactor (reactor wall) have a large surface areawith respect to reactor volume, and a diffusion distance (a distancebetween the reaction species passing through the reactor and the reactorwall) is short. With this structure, by causing the reactor wall tosupport a catalyst, for example, it is possible to increase area ofcontact between the reaction species and the catalyst, and thereby allowfor high-efficiency catalyst reactions. Therefore, the micro reactordevice is regarded as a promising catalyst reactor device.

It is a common practice to cause the reactor wall to support thecatalyst by a sol-gel method, in using the micro reactor device as acatalyst reactor device as described above.

However, according to this supporting method, an area on which thecatalyst is supported is only as large as the surface area of thereactor wall of the reactor as a flow path. As a result, there is aproblem that only a limited amount of catalyst can be supported.

Even if the amount of catalyst is increased by causing the reactor wallto support a thicker layer of catalyst, there is a problem that almostonly the catalyst exposed on the surface of the catalyst layer can beused for catalyst reactions, because a significant pressure loss iscaused inside the catalyst layer.

If it is necessary to control a very short reaction time, such as apartial oxidization time, a diffusion time of the reaction species inthe catalyst varies. Therefore, there is a problem that a contact timevaries, resulting in various kinds of reaction products.

Moreover, the method of supporting the catalyst has a problem thatcomplex operation is required in order to expose the catalyst directlyto the reactor wall.

The present invention was made in view of the foregoing problems. Anobject of the present invention is to provide a method of manufacturinga micro reactor device having an inner wall modified so that reactionspecies can react more efficiently, and to provide the micro reactordevice.

DISCLOSURE OF INVENTION

As a result of diligent study on a method of supporting a catalyst on awall of a flow path, the inventors of the present invention found that adeposition layer including particles (particle layer) can be formed onthe inner wall of the reactor of the micro reactor device, and reachedthe present invention.

To solve the foregoing problems, a method of the present invention formanufacturing a micro reactor device that includes a tubular reactor asa flow path and allows reaction species to react in the reactor includesthe step of: forming a particle layer including particles on an innerwall of the reactor. It is preferable that the particle layer is formedby causing a dispersion liquid of particles to flow through the reactorand drying the reactor (drying the dispersion liquid). The tubularreactor has a hollow structure, so as to allow a predetermined materialto pass therethrough.

It is preferable that a solvent of the dispersion liquid is a mixedsolvent including at least two kinds of solvents. By thus using a mixedsolvent including at least two kinds of solvents, it is possible toadjust the drying rate of the dispersion liquid.

It is preferable that the flow path has a cross section of a round orelliptical shape. In this way, it is possible to make the meniscus havea more even shape and thereby control the thickness of the particlelayer evenly.

The particles themselves may be a catalyst, or a functional material,such as a catalyst, may be supported by the particle layer. With thisarrangement, the micro reactor device can be used as a catalyst reactordevice. In this case, since there are spaces between the particles inthe particle layer, the area of contact between the reaction species andthe catalyst that occurs when the reaction species pass through thereactor is large. Therefore, it is possible to increase the efficiencyof catalyst reactions. Even in the case of a very short reaction such aspartial oxidization, it is possible to reduce variation of thedispersion time of the reaction species in the catalyst and the contacttime of the reaction species with the catalyst. As a result, it ispossible to reduce variation of the kinds of reaction products. Sincethe variation of the dispersion time of the reaction species can also bereduced in this case, it is preferable that the spaces are structuredregularly. In other words, it is preferable that, in the particle layer,particles having even diameters are aligned regularly.

The foregoing method may have an arrangement in which a hydrophilicityprocess and a hydrophobicity process are performed on desired regions ofthe inner wall of the reactor, and a water dispersion liquid ofparticles is caused to flow through the reactor. With this arrangement,a patterned particle layer can be formed on the inner wall of thereactor. By thus providing a patterned particle layer, more precise andcomplex reactions of the reaction species are made possible.

The particles may be a conductive material, and electrodes may be formedby sintering the particles. Furthermore, the electrodes may be used as asensor. With these arrangements, the micro reactor device can, forexample, produce a material by electrochemical reactions and/or detectreactions. Also in this case, it is preferable that the particles in theparticle layer are aligned regularly and densely, so as to obtainhigh-density electrodes by low-temperature sintering.

The foregoing method may have an arrangement in which, using theparticle layer as a mold, a layer is formed by filling spaces betweenthe particles of the particle layer with sol or nanoparticles andsolidifying the sol or nanoparticles, and the particles of the particlelayer are removed. The nanoparticles are particles whose diameters arebetween several nanometers and ten or so nanometers.

The sol or nanoparticles are not particularly limited, as long as theycan be filled into the spaces between the particles of the particlelayer and solidified. By using latex beads, for example, as theparticles, it is possible to remove the particles by thermaldecomposition. If gel is used, in particular, the layer (layer formed byfilling and solidifying the sol or nanoparticles) is a gel layer. Inthis case, after the particle layer is removed, pores are formed bythose parts where the particles existed. The gel layer may support afunctional material such as a catalyst. When the reaction species passthrough the gel layer, area of contact between the reaction species andthe catalyst is large, due to the pores. This can increase efficiency ofcatalyst reactions. If the nanoparticles are used, a layer can be formedby solidifying the nanoparticles by sintering. Therefore, the sameeffect as that of the gel layer can be attained.

To solve the foregoing problems, a micro reactor device of the presentinvention, including a tubular reactor as a flow path, for allowingreaction species to react in the reactor, further includes: a particlelayer including particles, provided on an inner wall of the reactor.

It is preferable that the flow path has a diameter between 1 μm and 1mm. With this arrangement, it is possible to reduce pressure loss andmaintain appropriate dispersion time of the reaction species. Therefore,it is possible to provide a good reactor.

It is preferable that the particles of the particle layer have adiameter between 1 nm and 10 μm. With this arrangement, it is possibleto deposit the particles evenly and thereby form an even particle layer.In addition, since the particles do not peel off easily, it is possibleto prevent the loss of the particle layer.

It is preferable that the particle layer has a thickness of not morethan 5 μm. If the thickness of the particle layer is more than 5 μm, theparticle layer cracks easily, and there is a possibility that theparticle layer is lost from the inner wall of the reactor.

It is preferable that the particles are a catalyst. Moreover, it ispreferable that the particles are composite particles supporting afunctional material such as a catalyst. With these arrangements, themicro reactor device can be used as a catalyst reactor device. In thiscase, since there are spaces between the particles in the particlelayer, the area of contact between the reaction species and the catalystthat occurs when the reaction species pass through the reactor is large.Therefore, it is possible to increase the efficiency of catalystreactions. Even in the case of a very short reaction such as partialoxidization, it is possible to reduce variation of the dispersion timeof the reaction species in the catalyst and the contact time of thereaction species with the catalyst. As a result, it is possible toreduce variation of the kinds of reaction products.

It is preferable that the particle layer is patterned. By thus providinga patterned particle layer, more precise and complex reactions of thereaction species are made possible.

A micro reactor device of the present invention, including a tubularreactor as a flow path, for allowing reaction species to react in thereactor, further includes: patterned electrodes provided in an innerwall of the reactor.

With this arrangement, the electrodes can be used as a sensor, and themicro reactor device can, for example, produce a material byelectrochemical reactions and/or detect reactions.

A micro reactor device of the present invention, including a tubularreactor as a flow path, for allowing reaction species to react in thereactor, further includes: a layer having particle-shaped pores,provided on an inner wall of the reactor.

According to this arrangement, the layer can support a functionalmaterial such as a catalyst, because the layer has the particle-shapedpores. When the reaction species pass through this layer, area ofcontact between the reaction species and the catalyst is large, due tothe pores. This can increase efficiency of catalyst reactions.

For a fuller understanding of the nature and advantages of theinvention, reference should be made to the ensuing detailed descriptiontaken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectional view of a major part of a micro reactor ofone embodiment of the present invention.

FIGS. 2(a) and 2(b) are diagrams illustrating a step of forming aparticle layer in the micro reactor of the present invention.

FIG. 3 is a cross-sectional view of a major part of a micro reactor ofanother embodiment of the present invention.

FIG. 4 is a cross-sectional view of a major part of a micro reactor ofyet another embodiment of the present invention.

FIGS. 5(a) and 5(b) are images of a particle layer formed in EXAMPLE 1.

FIG. 6 is an image of composite particles of EXAMPLE 8.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1

With reference to FIGS. 1, 2(a), and 2(b), the following describes oneembodiment of the present invention.

As shown in FIG. 1, a micro reactor (micro reactor device) of thepresent embodiment has a tubular reactor 1 as a reaction field. Thereactor 1 has a particle layer 2 including a plurality of particlesaligned on an inner wall of the reactor 1. In this reactor, variouskinds of reaction species can be reacted by passing through the reactor1 as a flow path. The tubular reactor 1 has a hollow for allowingpredetermined materials to pass therethrough.

With reference to FIGS. 2(a) and 2(b), the following describes a methodof manufacturing the particle layer 2 of the reactor 1 (method ofmanufacturing a micro reactor). Discussed below is a case in which theparticles are charged negatively and the inner wall of the reactor ischarged negatively.

First, a solution (dispersion liquid) containing fine particlesdispersed in a solvent is poured into the reactor 1. In the presentembodiment, the dispersion liquid is a colloidal solution. Thedispersion liquid includes a suspension and the like.

Next, as shown in FIG. 2(a), a gas-liquid surface is gradually movedwhile a colloidal solution 3 is dried. In this way, fine particles aredeposited on the inner wall of the reactor 1 and thereby form theparticle layer 2.

More specifically, as shown in FIG. 2(b), fine particles 2 a in thecolloidal solution 3 are separated from each other due to repulsiveforce. Where the amount of the colloidal solution 3 is large, the fineparticles 2 a and the inner wall of the reactor 1 are separated due torepulsive force. Meanwhile, the gas-liquid surface forms a meniscus. Ata part of the meniscus that contacts the inner wall, the colloidalsolution 3 is thin. Therefore, the solvent of the colloidal solution 3is evaporated, and the fine particles 2 a are adsorbed to the inner wallof the reactor 1 due to advectional assembly and lateral capillaryforce. Then, the fine particles 2 a are aligned on the inner wall of thereactor 1 and thereby form the particle layer 2. The particle layer 2can be formed at such a part that has excellent wettability with thecolloidal solution and forms a thin meniscus. The diameter of the flowpath is preferably not smaller than 1 μm and preferably not larger than1 mm. If the diameter of the flow path is smaller than 1 μm, thepressure loss is so significant that the micro reactor cannot be used.On the other hand, if the diameter of the flow path is larger than 1 mm,the diffusion time of the reaction species is so long thatcharacteristics of the micro reactor cannot be attained. Thus, bydesigning the diameter of the flow path to be not smaller than 1 μm andnot larger than 1 mm, it is possible to reduce the pressure loss in themicro reactor and thereby maintain an appropriate diffusion time of thereaction species.

Even if the fine particles 2 a have various diameters, the fineparticles 2 a can be aligned as the particle layer 2. If the fineparticles 2 a have a uniform diameter, it is possible to align the fineparticles 2 a more evenly and regularly. If the fine particles 2 a aremonodisperse in the colloidal solution 3, it is possible to align thefine particles 2 a yet more evenly and regularly. It is preferable thatthe diameter of the fine particles 2 a is between 1 nm and 10 μm. It isproblematic to regard the fine particles 2 a as particles when thediameter of the fine particles 2 a is smaller than 1 nm. In thisspecification, therefore, the fine particles 2 a are regarded asparticles when the diameter of the fine particles 2 a is not smallerthan 1 nm. If the diameter of the fine particles 2 a is larger than 10μm, it is difficult to deposit the particles evenly, hence to form theparticle layer 2 evenly. In addition, the particle layer 2 could be lostbecause the particles could peel off the inner wall easily.

The thickness of the particle layer 2 is determined by the shape of themeniscus on the gas-liquid surface under drying. therefore, in order tomake the thickness of the particle layer 2 even, it is preferable that across-section of the reactor 1 is round or elliptical, so that themeniscus has a more even shape.

The thickness of the particle layer 2 can be adjusted freely between asingle-particle layer (that is, the diameter of the particles 2 a) andabout 20 μm, by adjusting the evaporation rate of the solvent of thecolloidal solution 3 and/or the concentration of the fine particles 2 ain forming the particle layer 2. In order to adjust the evaporation rateof the solvent of the colloidal solution 3, heat may be applied duringevaporation. The thickness of the particle layer 2 is preferably notmore than 20 μm. If the thickness of the particle layer 2 is more than20 μm, the particle layer 2 cracks easily, and there is a possibilitythat the particle layer 2 is lost from the inner wall of the reactor 1.It is preferable that the particle layer 2 can completely cover theinner wall of the reactor 1, because this prevents loss of the particlelayer 2 even if the particle layer 2 cracks.

The length of the particle layer 2 (length in a traveling direction ofthe reaction species in the reactor 1) is basically not limited.However, considering a practical drying rate and a time required forpreparation of the particle layer 2, a preferable length of the particlelayer 2 is not more than 20 m.

The reactor 1 may be made of a commonly used material; namely, metal,ceramics, polymer molecules, and the like material that can form a tubeshape. It is preferable that the reactor 1 is made of such a materialthat does not hinder reactions of the reaction species.

For example, the fine particles 2 a may be a ceramic material such assilica, titania, alumina, tin oxide, zinc oxide, zinc sulphide, andcadmium selenide; a metal material such as platinum, gold, silver, andcopper; or a polymeric material such as polymethyl methacrylic acid,polystyrene, and protein. It is preferable that the fine particles 2 aare made of such a material that does not hinder reactions of thereaction species.

The fine particles 2 a may be composite particles obtained by combiningbase material particles and a functional material. In other words, thefine particles 2 a may be composite particles in which a functionalmaterial is supported by base material particles. In this way, it ispossible to form the particle layer 2 by using composite particles.

It is preferable that the composite particles are covered particles inwhich a surface of base material particles is covered with a functionalmaterial. In other words, it is preferable that the composite particlesare covered particles having a core-shell structure, in which a surfaceof core particles of a base material is covered. Since the coveredparticles are covered with a functional material, it is possible toreact efficiently the functional material and a compound that can reactwith the functional material.

It is preferable that the particle diameter of the functional materialis smaller than the particle diameter of the particles. In this way,each particle can support (can be covered with, preferably) a largeramount of the functional material. As a result, reactivity of theparticle layer is improved.

The functional material may be determined appropriately in accordancewith the reaction species that pass through the flow path of the microreactor. Examples of the functional material include a catalyst andbiofunctional materials such as protein and enzyme. Examples of thecatalyst include metal compounds such as titania and cadmium selenide;and metals such as platinum, palladium, and nickel. Examples of thebiofunctional materials such as protein and enzyme include trypsin andlipase.

The composite particles can be manufactured easily by aheterocoagulation method. However, a method of manufacturing thecomposite particles is not particularly limited. If the compositeparticles are to be manufactured by the heterocoagulation method, it ispreferable to control charges on the surface of the particles supportedby or covered with the functional material, by using a surface-activeagent. More specifically, for example, it is preferable to modify thecharges on the surface of the core particles so that the charges on thesurface of the core particles become different from charges of thefunctional material. In this way, the functional material can besupported on, or provided so as to cover, the surface of the coreparticles efficiently. The surface-active agent may be set appropriatelyin accordance with the charges of the core particles, with no particularlimitation. Examples of the surface-active agent includepolyethyleneimide, polyvinyl acetate, and polyvinylpyrrolidone.

Instead of forming the particle layer by using the composite particlessupporting or covered with the functional group, the functional materialmay be adsorbed to the fine particles 2 a after the fine particles 2 aare adsorbed to the inner wall of the micro reactor.

As the solvent of the colloidal solution 3, it is necessary to choose adispersion medium (solvent) that can stably disperse the fine particles2 a. The dispersion medium may be selected, for example, from commonlyused dispersion mediums such as water, ethanol, acetone, toluene,hexane, and chloroform, and a mixed solvent of these dispersion mediums.In order to improve stability of the fine particles 2 a in thedispersion medium, a surface-active agent such as polyethyleneglycol maybe added to the dispersion medium, if appropriate. By using a mixedsolvent, it is possible to adjust the drying rate of the dispersionliquid.

If the fine particles 2 a are a catalyst, the micro reactor functions asa catalyst reactor device. Examples of a catalysis of the catalystinclude a photocatalysis, a contact oxidative reaction, a partialoxidative reaction, and an electrocatalysis. In the particle layer 2,the fine particles 2 a are aligned, with spaces therebetween. Thus, whenthe reaction species pass through the micro reactor, the reactionspecies can contact almost all of the fine particles 2 a. This makes thearea of contact of the catalyst very large, and thereby improvescatalyst efficiency. Therefore, in the case of a very short reactionsuch as partial oxidization, it is possible to reduce variation of thedispersion time of the reaction species in the catalyst. By reducing thevariation of the dispersion time of the reaction species, it is possibleto reduce variation of the kinds of reaction products. Thus, it ispossible to control reactions.

If the fine particles 2 a is aligned regularly in the particle layer 2,the catalyst can be distributed evenly. Therefore, it is possible toattain an even pore size distribution and thereby increase uniformityand controllability of the reactions.

The particle layer 2 can be formed at such a part that has excellentwettability with the colloidal solution 3 and forms a thin meniscus. Onthe other hand, the particle layer 2 cannot be formed at such a partthat does not have excellent wettability with the colloidal solution 3.In view of this characteristic, the particle layer 2 can be patterned bydesigning the inner wall of the reactor 1 so as to have a part that haswettability with the colloidal solution 3 and a part that does not havewettability with the colloidal solution 3. Specifically, the part wherethe particle layer 2 is to be formed is designed so as to havewettability with the colloidal solution 3, and the other parts aredesigned so as not to have wettability with the colloidal solution 3. Bythus controlling the wettability of the inner wall of the reactor 1 andcontrolling the shape of the meniscus, it is possible to form theparticle layer 2 having a desired shape in a desired position on theinner wall of the reactor 1.

Specifically, the particle layer 2 can be patterned by controllinghydrophobicity and hydrophilicity of the inner wall of the reactor 1.More specifically, the inner wall of the reactor 1 is subjected to ahydrophobicity process and a hydrophilicity process. Then, a colloidalsolution 3 containing water as a solvent is poured into the reactor 1.By dying the colloidal solution 3 while controlling the shape of themeniscus, it is possible to form the particle layer 2 only at the partsubjected to the hydrophilicity process.

In this way, the particle layer 2 having a desired shape can be formedin a desired position of the inner wall of the reactor 1. Therefore, itis possible to cause more accurate and complex reactions.

The particle layer 2 can be formed also by a heterocoagulation method inwhich the particles are agglutinated to the inner wall of the reactor 1by electrostatic repulsive force, a method in which the particles arechemically bonded to the inner wall of the reactor, or the like method.

Embodiment 2

With reference to FIG. 3, the following describes another embodiment ofthe present invention. For the purpose of explanation, members whosefunctions are identical to those of the members described in EMBODIMENT1 are labeled with identical reference marks, and explanation of thesemembers are omitted.

By providing such members as electrodes and/or a sensor inside thereactor of a micro reactor device, it is possible, for example, toproduce materials by electrochemical reactions, and/or to detectreactions. In order to provide the electrodes and/or the sensor insidethe reactor, it is necessary to perform such operation as spattering,and to use a complex device. In addition, depending on characteristicsof the spattering, only a limited material can be used, and structuresof the electrodes and/or the sensor are limited. If a capillary-typereactor is used in the micro reactor device that is a space closed bythe spattering as described above, it is very difficult to provide theelectrodes and/or the sensor inside the reactor.

In view of this problem, in the present embodiment, the particle layer 2of EMBODIMENT 1 is made of a metal material, for example, and the metalmaterial is sintered so as to form electrodes 4.

That is, as in EMBODIMENT 1, the particle layer 2 having a desired shapeis patterned in a desired position of the reactor 1, and the particlelayer 2 is sintered so as to form the electrodes 4, as shown in FIG. 3.

In this way, the electrodes 4 can be formed on the inner wall of themicro reactor, which is a closed space. As a result, it is possible, forexample, to produce materials by electrochemical reactions, and/or todetect reactions, in the reactor 1. In the colloidal solution 3, thefine particles may be a conductive material that can become a colloid.Examples of the fine particles in the colloidal solution 3 include metalnanoparticles such as gold nanoparticles, silver nanoparticles andcopper nanoparticles; conductive polymer nanoparticles such aspolyaniline and polypyrrole; conductive inorganic compound nanoparticlessuch as carbon colloid, tin oxide, indium-tin oxide; and compositenanoparticles in which these particles are mixed.

Embodiment 3

With reference to FIG. 4, the following describes yet another embodimentof the present invention.

For the purpose of explanation, members whose functions are identical tothose of the members described in EMBODIMENT 1 are labeled withidentical reference marks, and explanation of these members are omitted.

In the present embodiment, the particle layer 2 formed in EMBODIMENT 1is used as a mold, so as to form a layer having a high pore ratio. Then,the particles of the particle layer 2 are removed, and a functionalmaterial such as a catalyst is supported by the layer having a high poreratio. Thus, a functional material such as a catalyst is supported bythe inner wall of the micro reactor.

First, as described in EMBODIMENT 1, the particle layer 2 is formed. Thespaces between particles in the particle layer is filled with a materialsuch as fine particles (nanoparticles) and silica sol. The fineparticles or silica sol are solidified by drying or sintering, forexample, so as to form a layer. Then, the particles in the particlelayer are removed. In this way, as shown in FIG. 4, vacancies arecreated in the spaces where the particles existed. As a result, areverse opal shape layer 5 is formed. Thus, the layer 5 can be formed byusing the particle layer as a mold. In addition, the functional materialor the like can be supported by the vacancies. If the particles of theparticle film, which is used as a mold, are aligned basically, it isless likely that the movement speed of the reaction species in the layervaries. This improves reaction controllability.

The particles can be removed if, for example, the particles are latexbeads and are thermally decomposed.

EXAMPLES

The following examples more specifically describe the present invention.Note, however, that the present invention is not limited to theseexamples.

Example 1

In the present example, a silica particle layer was formed on the innerwall of the reactor in the micro reactor of EMBODIMENT 1, and a platinumcatalyst was supported by the surface of the silica particle layer.

First, a suspension was prepared by causing silica particles (particlediameter: 0.15 μm) to be suspended in a mixed solvent of ethanol andwater (ethanol: water=1:9). The suspension was poured into thecapillary-type micro reactor, and dried at 80° C., so as to form asilica particle layer (particle layer) on the inner wall of the microreactor. The thickness of the silica particle layer could be adjusted byadjusting the drying temperature and/or the concentration of thesuspension. The thickness could be adjusted between a single-particlelayer (thickness: 0.15 μm) and a multi-particle layer (thickness: 5 μm).SEM photographs of the single-particle layer are shown in FIGS. 5(a) and5(b). From FIG. 5(a), it can be seen that silica particles are arrangedsubstantially evenly on the inner wall of the micro reactor. FIG. 5(b)shows the shape of a surface of the particle layer formed on the microreactor.

To the silica particles, which constituted the single-particle layer,platinum fine particles were adsorbed.

In the micro reactor having the silica particle layer with the platinumfine particles adsorbed thereto, ethylene was hydrogenated. The reactionrate was 1.5 times higher than that of the case in which a platinum fineparticle layer, instead of the silica particle layer, was adsorbed tothe inner wall of the micro reactor.

Example 2

In the present example, a CdSe particle layer was formed on the innerwall of the reactor in the micro reactor of EMBODIMENT 1.

First, a chloroform suspension including CdSe particles (averageparticle diameter: 2 nm) was prepared. The suspension was poured intothe capillary-type micro reactor, and dried at a room temperature, so asto form a CdSe particle layer on the inner wall of the micro reactor.The thickness of the CdSe particle layer could be changed between 10 nmand 50 nm.

Example 3

In the present example, a patterned silica particle layer was formed onthe inner wall of the reactor in the micro reactor of EMBODIMENT 1.

First, hydrophobicity was given to the inner wall of the capillary-typemicro reactor by surface processing with trimethoxydodecylsilane. Then,the inner wall was covered with a patterning mask, and ultraviolet rayswere radiated, so as to give hydrophilicity to the irradiated portion.Next, a suspension including silica particles, which had been preparedin advance as in EXAMPLE 1, was poured into the micro reactor, and driedat 80° C. As a result, a patterned silica particle layer was formed onthe hydrophilic portion of the inner wall of the micro reactor.

Example 4

In the present example, patterned gold electrodes were formed on theinner wall of the reactor in the micro reactor of EMBODIMENT 2.

First, hydrophobicity was given to the inner wall of the capillary-typemicro reactor by surface processing with trimethoxydodecylsilane. Then,the inner wall was covered with a patterning mask, and ultraviolet rayswere radiated, so as to give hydrophilicity to the irradiated portion.Next, a suspension including gold nanoparticles (particle diameter: 12nm), which had been prepared in advance, was poured into the microreactor, and dried at 80° C. As a result, a patterned gold particlelayer, in which the gold nanoparticles were aligned, was formed only onthe hydrophilic portion.

By sintering the gold particle layer of the micro reactor at 400° C., agold film was obtained. The conductivity of the gold film, measured by adirect current four-electrode method, was 3×10⁷ (S/m), which is a valuesufficiently practical for electrodes.

Example 5

In the present example, a silica gel layer was formed on the inner wallof the reactor in the micro reactor of EMBODIMENT 3, and trypsin wassupported by the silica gel layer.

First, 1% by weight of latex beads water suspension was poured into thecapillary-type micro reactor and dried, so as to form a latex particlelayer on the inner wall of the micro reactor, as in EXAMPLE 1. Then, asol solution, in which trimethoxysilane, ethanol, water, andhydrochloric acid were mixed(trimethoxysilane:ethanol:water:hydrochloric acid=1:1:0.5:0.0005), wascaused to pass through the micro reactor, so that spaces between thelatex particles in the latex particle layer were filled with sol bycapillary force. By drying the sol and thereby obtaining silica gel, asilica gel layer was formed. Then, the latex particles were thermallydecomposed by heating at 600° C. in an airflow of oxygen. Those partswhere the latex particles had existed were turned into pores. Thus, asilica gel layer having a so-called reverse opal structure was obtained.Subsequently, trypsin was supported by the silica gel layer having thereverse opal structure.

The trypsin was supported by the following method.

First, by hydrolyzing aminopropylsilane on the surface of the silica gellayer, amino groups were supported by the surface of the silica gellayer. Then, by reacting succinic anhydride with the amino groups,carboxyl groups were introduced onto the surface of the silica gellayer. Further, by reacting the carboxyl groups with trypsin, thetrypsin was supported by the surface of the silica gel layer throughcovalent bonding.

In the micro reactor having the silica gel layer supporting trypsin,benzoylarginineparanitroanilide (BAPA) was decomposed. The reaction ratewas six times higher than that of the case in which trypsin alone wasprovided to the micro reactor without forming the silica gel layer. Thatis, by supporting trypsin by the silica gel layer having the reverseopal structure, the reaction rate became six times higher.

Example 6

In the present example, a titania gel layer was formed on the inner wallof the reactor in the micro reactor of EMBODIMENT 3.

First, 50% by weight of latex beads water suspension was poured into thecapillary-type micro reactor and dried, so as to form a latex particlelayer on the inner wall of the micro reactor. The thickness of the latexparticle layer was about 1 μm, so as to cover the inner wall of themicro reactor completely. Then, by impregnating the latex particle layerwith titania sol in which titanium isopropoxide, ethanol, water, andhydrochloric acid were mixed, spaces between the latex particles in thelatex particle layer were filled with the titania sol. Next, the titaniasol was dried to obtain tinania gel. After that, the latex particleswere thermally decomposed by heating at 600° C. In this way, those partswhere the latex particles had existed were turned into pores. Thus, atitania gel layer having a so-called reverse opal structure wasobtained.

While radiating ultraviolet rays (wavelength: 360 nm), metane gas andoxygen were caused to simultaneously pass through the micro reactorhaving the titania gel layer. As a result, methanol was obtained at 5%yield.

Example 7

In the present example, a silica gel layer supporting titania was formedon the inner wall of the reactor in the micro reactor of EMBODIMENT 3.

First, a 50%-by-weight suspension of latex beads to which anatase-typetitania was adsorbed by a heterocoagulation method was prepared. Thesuspension was poured into the capillary-type micro reactor and dried,so as to form a latex particle layer supporting titania, on the innerwall of the micro reactor. Then, a sol solution, in whichtetramethoxysilane: ethanol, water, and hydrochloric acid were mixed(tetramethoxysilane:ethanol:water:hydrochloric acid=1:1:0.5:0.0005), wascaused to pass through the micro reactor, so that spaces between thelatex particles in the latex particle layer were filled with sol bycapillary force. By drying the sol and thereby obtaining silica gel, asilica gel layer was formed. Then, the latex particles were thermallydecomposed by heating at 600° C. in an airflow of oxygen. Those partswhere the latex particles had existed were turned into pores. Thus, asilica gel layer having a so-called reverse opal structure was obtained.At this time, titania remained and was supported by the silica gellayer.

While radiating ultraviolet rays (wavelength: 360 nm), metane gas andoxygen were caused to simultaneously pass through the micro reactorhaving the silica gel layer supporting titania. As a result, methanolwas obtained at 4% yield.

Example 8

In the present example, titatia nanoparticles were formed as compositeparticles (cover particles) on the inner wall of the reactor in themicro reactor of EMBODIMENT 1.

First, negative surface charges of silica colloid (diameter: 120 nm) wasturned into positive charges by surface modification withpolyethyleneimide. Then, anatase-type titania nanoparticles (particlediameter: 20 nm), which also had negative charges, were supported by thesilica colloid, so as to form composite particles. FIG. 6 is an SEMimage of the composite particles. Subsequently, the composite particleswere suspended in a mixed solvent of ethanol and water (ethanol:water=6:4). The mixed solvent was poured into capillaries (200 μm and530 μm) and dried. As a result, a micro reactor having titaniananoparticles supported by the inner wall of the capillaries wasobtained. By using the micro reactor, methylene blue was photolyzed. Thedecomposition rate was much higher in each capillary than that of thecase in which the micro reactor was not used. In particular, if the 200μm capillary was used, methylene blue was photolyzed at a rate 150 timeshigher than that of the case in which the micro reactor was not used.

The specific embodiments and examples in BEST MODE FOR CARRYING OUT THEINVENTION section are described only for clarifying technical contentsof the present invention. The present invention should not beinterpreted as being limited to these specific examples. The presentinvention may be carried out in various ways within the scope of thespirit of the present invention and the following claims.

INDUSTRIAL APPLICABILITY

The micro reactor device of the present invention can realize a catalystreactor device having a particle layer on the inner wall of the microreactor device, the particle layer having spaces on the order of severalnanometer to several micrometer. This can improve efficiency of catalystreactions. In addition, since surface modification and patterning can beperformed on the inner wall of the micro reactor device, precisereaction control is possible. There is also an effect that electrodescan be provided easily to the micro reactor device.

1. A method of manufacturing a micro reactor device that includes atubular reactor as a flow path and allows reaction species to react inthe reactor, the method comprising the step of: forming a particle layerincluding particles on an inner wall of the reactor.
 2. The method asset forth in claim 1, wherein: the particle layer is formed by causing adispersion liquid of particles to flow through the reactor and dryingthe reactor.
 3. The method as set forth in claim 1, wherein: in theparticle layer, the particles are aligned regularly.
 4. The method asset forth in claim 1, wherein: a solvent of the dispersion liquid is amixed solvent including at least two kinds of solvents.
 5. The method asset forth in claim 1, wherein: the flow path has a cross section of around or elliptical shape.
 6. The method as set forth in claim 1,wherein: the particles are a catalyst.
 7. The method as set forth inclaim 1, wherein: a catalyst is supported by the particle layer.
 8. Themethod as set forth in claim 1, wherein: the particle layer includescomposite particles formed by supporting a functional material by theparticles.
 9. The method as set forth in claim 8, wherein: in thecomposite particles, the functional material covers the particles. 10.The method as set forth in claim 8, wherein: the composite particles areformed by a heterocoagulation method.
 11. The method as set forth inclaim 8, wherein, the composite particles are formed by controlling asurface charge of the particles by a surface-active agent.
 12. Themethod as set forth in claim 1, wherein: a hydrophilicity process and ahydrophobicity process are performed on desired regions of the innerwall of the reactor, and a water dispersion liquid of particles iscaused to flow through the reactor.
 13. The method as set forth in claim12, wherein: the particles are a conductive material, and electrodes areformed by sintering the particles.
 14. The method as set forth in claim1, wherein: using the particle layer as a mold, a layer is formed byfilling spaces between the particles of the particle layer with sol ornanoparticles and solidifying the sol or nanoparticles, and theparticles of the particle layer are removed.
 15. The method as set forthin claim 14, wherein: the particles are removed by thermaldecomposition.
 16. The method as set forth in claim 14, wherein: acatalyst is supported by the layer formed by filling and solidifying thesol or nanoparticles.
 17. A micro reactor device, comprising a tubularreactor as a flow path, for allowing reaction species to react in thereactor, the micro reactor device further comprising: a particle layerincluding particles, provided on an inner wall of the reactor.
 18. Themicro reactor device as set forth in claim 17, wherein: in the particlelayer, the particles are aligned regularly.
 19. The micro reactor deviceas set forth in claim 17, wherein: the flow path has a diameter between1 μm and 1 mm.
 20. The micro reactor device as set forth in claim 17,wherein: the particles of the particle layer have a diameter between 1nm and 10 μm.
 21. The micro reactor device as set forth in claim 17,wherein: the particle layer has a thickness of not more than 20 μm. 22.The micro reactor device as set forth in claim 17, wherein: theparticles are a catalyst.
 23. The micro reactor device as set forth inclaim 17, wherein: the particles are composite particles supporting afunctional material.
 24. The micro reactor device as set forth in claim23, wherein: the composite particles are covered particles that are theparticles covered with the functional material.
 25. The micro reactordevice as set forth in claim 17, wherein: the particle layer ispatterned.
 26. A micro reactor device, comprising a tubular reactor as aflow path, for allowing reaction species to react in the reactor, themicro reactor device further comprising: electrodes made of particles,provided on an inner wall of the reactor.
 27. The micro reactor deviceas set forth in claim 26, wherein: the electrodes are patterned.
 28. Amicro reactor device, comprising a tubular reactor as a flow path, forallowing reaction species to react in the reactor, the micro reactordevice further comprising: a layer having particle-shaped pores,provided on an inner wall of the reactor.
 29. The micro reactor deviceas set forth in claim 28, wherein: the particle-shaped pores are alignedregularly.